CANNULA FOR TISSUE DISRUPTION
20170224317 · 2017-08-10
Assignee
Inventors
Cpc classification
A61B10/025
HUMAN NECESSITIES
A61B10/0283
HUMAN NECESSITIES
A61B2017/320024
HUMAN NECESSITIES
International classification
Abstract
A coiled shaft for tissue disruption is described herein where a flexible aspiration cannula has a first portion and a second portion formed of the coiled shaft. The cannula is configured in a particular embodiment to rotate over the length of the cannula to disrupt the matrix of bone marrow without the cannula buckling or collapsing. The cannula also includes a disruption tip coupled to the coiled shaft. The disruption tip has a radiused portion along a distal tip face of the disruption tip.
Claims
1. An aspiration cannula for tissue disruption, comprising: a first portion having a first length and a first stiffness: a second portion having a second length attached to the first portion, the second length having a second stiffness which is less than the first stiffness; and a disruption tip attached to a distal end of the second portion, the disruption tip having a radiused portion and the disruption tip defining one or more openings which is in fluid communication with an aspiration lumen defined through the first length and the second length.
2. The cannula of claim 1, wherein the radiused portion includes a plurality of radiused corners.
3. The cannula of claim 2, wherein each of the radiused corners has a radius between 0.005 in. and 0.010 in.
4. The cannula of claim 1, wherein the radiused portion includes a singular radiused edge.
5. The cannula of claim 1, wherein the radiused portion extends over an arc length defined by a central arc angle.
6. The cannula of claim 5, wherein the central arc angle can be between 100° and 120°.
7. The cannula of claim 5, wherein the central arc angle can be 180° and the radiused portion can extend over the entire arc length.
8. The cannula of claim 1, wherein the disruption tip has a device radius in a dimensional plane orthogonal to the dimensional plane of the radiused portion.
9. The cannula of claim 8, wherein the device radius is 0.0635 in.
10. The cannula of claim 1, wherein the disruption tip includes a tip base and the disruption tip is welded to the second portion via the tip base.
11. The cannula of claim 1, wherein the disruption tip has a thickness of 0.032 in.
12. An aspiration cannula for tissue disruption, comprising: a first portion having a first length and a first stiffness: a second portion having a second length attached to the first portion, the second length having a second stiffness which is less than the first stiffness; and a disruption tip attached to a distal end of the second portion and having a thickness of 0.032 in., wherein the disruption tip has a radiused portion of between 0.005 in. and 0.010 in. which extends over a central arc of between 100° and 120° such that the disruption tip is configured to redirect the cannula in one or more directions while rotated about a longitudinal axis upon encountering a surface.
13. The cannula of claim 12, wherein the radiused portion includes a plurality of radiused corners.
14. The cannula of claim 12, wherein the radiused portion includes a singular radiused edge.
15. The cannula of claim 12, wherein the disruption tip has a device radius in a dimensional plane orthogonal to the dimensional plane of the radiused portion.
16. The cannula of claim 12, wherein the disruption tip includes a tip base and the disruption tip is welded to the second portion via the tip base.
17. The cannula of claim 12, wherein the disruption tip has a width of 0.127 in.
18. An aspiration cannula for tissue disruption, comprising: a first portion having a first length and a first stiffness; a second portion having a second length attached to the first portion, the second length having a second stiffness which is less than the first stiffness; and an aspirator tip attached to a distal end of the second portion, the aspirator tip defining one or more openings which is in fluid communication with an aspiration lumen defined through the first length, second length, and aspirator tip, wherein the second portion is formed of a single-layered coiled body formed at a first outer diameter and swaged to a second smaller outer diameter.
19. The cannula of claim 18 further comprising a hub attached to a proximal end of the first portion.
20. The cannula of claim 19 further comprising a handle removably attachable to the hub.
21. The cannula of claim 18 wherein the single-layered coiled body is comprised of 14 strands of wires positioned circumferentially adjacent to one another, each wire having a 0.016 in. wire diameter.
22. The cannula of claim 18 wherein the first outer diameter is 0.117 in. the second outer diameter is 0.112 in.
23. The cannula of claim 18 wherein the cannula is configured to rotate about a longitudinal axis at 150 rpm to 300 rpm.
24. The cannula of claim 23 wherein the cannula is configured to withstand a torque of 35 inch-ounces to 100 inch-ounces.
25. An aspiration cannula for tissue disruption, comprising: a first portion having a first length and a first stiffness; a second portion having a second length attached to the first portion, the second length formed of a single-layered coiled body having 14 strands of wires positioned circumferentially adjacent to one another and having a second stiffness which is less than the first stiffness; and an aspirator tip attached to a distal end of the second portion, the aspirator tip defining one or more openings which is in fluid communication with an aspiration lumen defined through the first length, second length, and aspirator tip, wherein the cannula is configured to rotate about a longitudinal axis at 150 rpm to 300 rpm and withstand a torque of 35 inch-ounces to 100 inch-ounces.
26. The cannula of claim 25 further comprising a hub attached to a proximal end of the first portion.
27. The cannula of claim 26 further comprising a handle removably attachable to the hub.
28. The cannula of claim 25 wherein each wire has a 0.016 in. wire diameter.
29. The cannula of claim 25 wherein the second portion is formed of a single-layered coiled body formed at a first outer diameter and swaged to a second smaller outer diameter.
30. The cannula of claim 29 wherein the first outer diameter is 0.117 in. and the second outer diameter is 0.112 in.
31. An aspiration cannula for tissue disruption, comprising: a first portion having a first length and a first stiffness; a second portion having a second length attached to the first portion, the second length formed of a single-layered coiled body having 14 strands of wires positioned circumferentially adjacent to one another and having a second stiffness which is less than the first stiffness; and an aspirator tip attached to a distal end of the second portion, the aspirator tip defining one or more openings which is in fluid communication with an aspiration lumen defined through the first length, second length, and aspirator tip, wherein the second portion has a flexibility which is sufficient to redirect an orientation of the aspirator tip relative to the first portion when the aspirator tip encounters a surface while the aspiration cannula rotates about its longitudinal axis.
32. The cannula of claim 31 wherein the cannula is configured to rotate about the longitudinal axis at 150 rpm to 300 rpm and withstand a torque of 35 inch-ounces to 100 inch-ounces.
33. The cannula of claim 31 wherein the cannula is configured to rotate about the longitudinal axis at 220 rpm and withstand a torque of 65 inch-ounces.
34. The cannula of claim 33 wherein the cannula is configured to deflect about its longitudinal axis at less than 50 grams of force.
35. The cannula of claim 31 further comprising a hub attached to a proximal end of the first portion.
36. The cannula of claim 35 further comprising a handle removably attachable to the hub.
37. The cannula of claim 31 wherein each wire has a 0.016 in. wire diameter.
38. The cannula of claim 31 wherein the second portion is formed of a single-layered coiled body formed at a first outer diameter and swaged to a second smaller outer diameter.
39. The cannula of claim 38 wherein the first outer diameter is 0.117 in. and the second outer diameter is 0.112 in.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION OF THE INVENTION
[0057] Devices and methods for manipulation and extraction of body tissue from an enclosed body cavity (e.g., iliac, femur, humerus, other bone, or combinations thereof) are disclosed. The device can have a hollow introduction or entry cannula that can have a stylet. The introduction cannula and stylet can penetrate body tissue, such as the marrow space contained within the iliac. A flexible aspiration cannula can then be inserted through the introduction cannula into body tissue and can be advanced through the body cavity. During insertion and/or withdrawal of the aspiration cannula, the elongate shaft may be rotated about its longitudinal axis such that the distal tip of the shaft may break up the marrow tissue which may be then aspirated into one or more openings defined along the distal tip, through the shaft, and into a collection reservoir.
[0058]
[0059] In order to introduce the aspiration cannula 18 into the patient body, an access trocar 40 having a piercing tip on the stylet 42, as shown in the side view of
[0060] Further examples and details are shown in the following U.S. Pat. Nos. 7,462,181; 8,043,253; 8,109,919; 8,002,733; 9,131,925; as well as in the following U.S. Pat. Pubs. 2007/0276352; 2009/0030338; 2009/0131827; 2016/0000991. Each of these references is incorporated herein by reference in its entirety and for any purpose.
[0061] The aspiration cannula 18 may be formed from a first portion 20 which extends distally from a hub 12 which is removably attachable to the handle 10. A proximal end of a second portion 24 may be joined to a distal end of the first portion 20 along a transitional portion 22. The first portion 20 may have a stiffness which is greater than a stiffness of the second portion 24 so that the proximal portion of the cannula 18 is able to provide structural stiffness to the cannula 18 while the second portion 24 is able to retain sufficient flexibility to maneuver within the bone cavity while retaining enough stiffness for torque transmission from the handle 10 to the distally positioned aspirator tip 28, as gauged against the stall torque limit.
[0062] The first portion 20 may be comprised of, e.g., a stainless steel hypotube, while the second portion 24 may be comprised of, e.g., a coiled shaft made also made from stainless steel. Similarly, the aspirator tip 28 may also be comprised of, e.g., stainless steel. Moreover, the first portion 20 may be formed to extend from the hub 12 at a length of, e.g., 3.600 in., while the second portion 24 may extend at a length of, e.g., 3.255 in. The total combined length of the aspiration cannula 18, including the aspirator tip 28, may have a length of, e.g., 7.225 in. Because of the coiled body of the second portion 24, a jacket, covering, or coating 26 (e.g., NYLON) may be placed over the second portion 24 to provide for a smooth and atraumatic surface as well as to provide for additional stiffness to the portion 24. Hence, the outer diameter of the aspiration cannula 18 may be, e.g., 0.127 in. The jacket, covering, or coating 26 also seals the lumen defined by the coiled body for creating a fluid path through the aspiration cannula 18. Additionally, the coiled body may further include a coating or layer, e.g., silicone, placed upon the inner diameter of the coiled body as well.
[0063] While the handle 10 may enclose a motor and electronics, such as a processor or controller to control any number of aspects of the assembly, the handle 10 may also be attached to an aspiration tube 30 such that one or more openings on the distally located aspirator tip 28 are in fluid communication through an aspiration lumen defined through the cannula 18, through the handle 10, and through the aspiration tube 30 to, e.g., a collection reservoir.
[0064] Tuning now to the details of the aspiration cannula 18,
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[0066] Turning now to the details of the coiled body of the second portion 24,
[0067] The wire coil is formed as a directional coil wound in a right-hand orientation relative to the longitudinal axis 70, as shown in
[0068] The coiled structure may be formed by multiple strands 76 of individual wires which are arranged circumferentially, as shown in the cross-sectional end view of
[0069] Moreover, the coiled wires are swaged for a reduced coil outer diameter when forming the coiled structure, as shown by the relatively flattened inner surface 72 and flattened outer surface 74. Swaging the coiled wires also reduces the diameter to a low profile and further helps to increase torque transfer along the length of the cannula 18.
[0070] Such coiled wires can be commercially manufactured (HHS® Tube, Fort Wayne Metals, Fort Wayne, Ind.). However, in one particular variation, the coiled structure is formed into a single-layered coiled body having 14 strands from a wire having a 0.016 in. diameter. The wire is wound to a 0.117 in. outer diameter and then swaged to have a 0.112 in. outer diameter and a 0.085 in. inner diameter. It is over this coiled structure that the jacket 26 is placed around.
[0071] Moreover, it is this combination of this particular coiled structure in the manner described and also the manner in which the second portion 24 is coupled to the first portion 20 that provides an aspiration cannula 18 which is able to rotate about its longitudinal axis optimally at 150 rpm to 300 rpm and preferably 220 rpm while also providing a torque range of 35 inch-ounces to 100 inch-ounces, and preferably 85 inch-ounces and more preferably 65 inch-ounces, which is the torque range for effectively rotating the aspirator tip 28 in the marrow tissues and maintaining the patency of the aspiration lumen 64 without having the aspiration cannula 18 buckle or collapse. This torque range has also been shown to be an ideal range for the aspiration cannula 18 and aspirator tip 28 to be advanced within the tissue and rotated for disrupting the tissue without damaging the cells and for aspirating them into the aspiration cannula 18.
[0072] The first portion 20 of the cannula 18 is shown in the detailed side view of
[0073] At the distal end of the second portion 24, the aspirator tip 28 may be attached over the coiled structure.
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[0075] As shown in
[0076] The surface of the tip base 100 as encompassed by the two lateral base sides 106 and the two longitudinal base sides 108 can be a substantially flat surface. In one variation, the surface of the tip base 100 can be substantially smooth. In other variations, the surface of the tip base 100 can be contoured, grooved, scored, scratched, perforated, or a combination thereof.
[0077] In one variation, the distal tip face 104, or a portion therein, can be shaped as an arc, such as a two-dimensional arc extending from one lateral base side 106 to the other lateral base side 106. The distal tip face 104 can abut or meet each of the tip sides 102 at a side edge 110.
[0078] The disruption tip 28 can have a radiused portion 112. The radiused portion 112 can include or encompass portions of the distal tip face 104, the side edges 110, the tip sides 102, or a combination thereof. The radiused portion 112 can be the most distal portion of the entire aspiration system. The radiused portion 112 will be discussed in more detail in the forthcoming sections.
[0079] The distal tip face 104 can abut or meet the tip sides 102 at an orthogonal or 90° angle. The distal tip face 104 can abut or meet the tip sides 102 at an orthogonal angle along portions of the distal tip face 104 not covered or encompassed by the radiused portion 112.
[0080] The distal tip face 104 can have a tip apex 114 as shown in
[0081] In one variation, the surfaces of the distal tip face 104, the tip sides 102, or a combination thereof can be substantially smooth. In other variations, the surfaces of the distal tip face 104, the tip sides 102, or a combination thereof can be contoured, grooved, scored, scratched, perforated, or a combination thereof.
[0082] Although not shown in
[0083] The disruption tip 28 can be fabricated from or made of stainless steel. In other variations, the disruption tip 28 can be fabricated from or made of a biocompatible polymer or polymer composite, a shape memory alloy, or a composite thereof.
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[0085] The transverse plane 128 can be an orientation plane bisecting the disruption tip 28 along a midsection of the disruption tip 28. The transverse plane 128 can intersect the disruption tip 28 along its radiused portion 112. The transverse plane 128 can also intersect the sagittal plane 126 along a line passing through the tip apex 114.
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[0087] The inferior horizontal plane 132 can be an orientation plane parallel to both the transverse plane 128 and the superior horizontal plane 130. The inferior horizontal plane 132 can be below (i.e., in the negative y-direction relative to) the transverse plane 128. As shown in
[0088] The orientation axes and planes will be used in
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[0090] The device radius 140 can extend from a midpoint 142 along the longitudinal base side 108 to any point along the side edge 110, the tip apex 114, or a combination thereof. The device radius 140 can be in a dimensional plane (e.g., the y-z plane) orthogonal to the dimensional plane of the radiused portion 112 (e.g., the x-z plane).
[0091] As shown in
[0092] The arc angle 144 can be represented or measured in degrees or radians. In one variation, the arc angle 144 can be between, e.g., 90° and 100°. For example, the arc angle 144 can be approximately 1000. In the variation shown in
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[0096] It should be noted that the distal portion of the disruption tip 28 can be defined by a combination of the device radius 140 along the y-z plane and the two radiused corners 150 along the x-z plane. When constructed as such, the distal portion of the disruption tip 28 can provide an atraumatic three-dimensional surface for disrupting a donor's cancellous bone matrix but not inadvertently penetrate the inner wall of the donor's cortical bone when the aspiration cannula 18 is driven through the cancellous bone.
[0097] In one variation, the same radiused corners 150 having the same corner radius 152 can define the entire arc length of the radiused portion 112. In this variation, taking a horizontal cross-section of any part of the disruption tip 28 along its radiused portion 112 can yield the contour shown in
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[0099] The singular edge radius 158 can be between, e.g., 0.012 in. and 0.018 in. For example, the singular edge radius 158 can be half the length of the lateral base side 106, or approximately 0.016 in.
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[0101] As shown in
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[0103] The tip base 100 can be welded directly to the distal ends of the multiple coil strands 76. In other variations, the tip base 100 can be coupled to the ends of the multiple coil strands 76 by adhesives, sealants, screws, clips, or a combination thereof.
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[0105] As shown in
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[0107] In other variations, the tip base 100 of the disruption tip 28 can be coupled or attached radially distal to the longitudinal axis 70. For example, the tip base 100 can be welded closer to a circumference of the coiled strands 76.
[0108] As shown in
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[0111] Although
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[0113] Another variation of the disruption tip is shown in the end, side and perspective views of
[0114] This disruption tip 180, when attached to the terminal or distal end of the second portion 24 of the aspiration cannula, as shown in the side and end views of
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[0117] Because the disruption tip and aspiration cannula are inserted into and advanced within cancellous bone, care is needed to ensure that the tip is not punctured through the cortical bone surrounding the cancellous bone during use. Hence, the assembly must have robust structural characteristics which enable the insertion, advancement, and rotation of the tip and cannula through the cancellous bone but which is still flexible enough so as to prevent or inhibit puncturing or drilling through the cortical bone.
[0118] For comparison, the relative strengths and mechanical properties of cancellous bone and cortical bone are shown below in Table 1.
TABLE-US-00001 TABLE 1 Mechanical properties of cortical and cancellous bone. PROPERTY CORTICAL BONE CANCELLOUS BONE Compressive Strength 100-230 MPa 2-12 MPa Flexural, 50-150 MPa 10-20 MPa Tensile Strength Strain to Failure 1-3% 5-7%
[0119] Because the disruption tip and aspiration cannula require robust structural characteristics which allow for operation of the device within the body, this difference in compressive strength, flexural strength, and strain to failure between cortical bone and cancellous bone creates a unique set of characteristics for the device to function properly. For example, the structural parameters of the device exceed the compressive strength and tensile strength of the cancellous bone to allow for its disruption and aspiration but the design of the device preferably allows for sufficient flexibility so that the compressive strength and tensile strength of the cortical bone is not exceeded during use and puncture or damage to the cortical bone is avoided or inhibited.
[0120] The disruption tip and aspiration cannula are designed in a manner which results in structural characteristics which accordingly enable the device to function suitably. The combination of structural characteristics, as described herein, present a device which is able to transmit the sufficient torque while also preventing the puncture of cortical bone. For instance, the described cannula is able to transmit a torque (e.g., 35 inch-ounces to 100 in-ounces, and preferably 85 inch-ounces and more preferably 65 inch-ounces) when rotated about its longitudinal axis at, e.g., 150 rpm to 300 rpm and preferably 220 rpm, which is sufficient to disrupt the cancellous bone. The aspiration cannula is able to withstand these torque values because of the manner in which the shaft is constructed with, e.g., 0.016 inch stainless steel wire, 14-strand, swaged torque coil, having a tip diameter of, e.g., 0.127 inch.
[0121] An example of one embodiment of the device having suitable characteristics to drill through cancellous bone is shown below in Table 2.
TABLE-US-00002 TABLE 2 Device characteristics for drilling through cancellous bone. Characteristics: Transmit Flexible shaft RPM Tip sufficient withstand Diameter torque relatively high torque value Attribute: 65 in-oz 0.016 in. ss wire, 220 0.127 in torque 14 strand, swaged range torque coil
[0122] While these parameters enable the tip and cannula to disrupt the cancellous bone, they also enable the device to avoid drilling through the surrounding cortical bone when the tip or shaft contacts the cortical bone surface. The characteristics of the disruption tip having the described radius, width, and diameter when being rotated at the described rate enables the cannula to present a flexibility of less than, e.g., 50 grams, to deflect the cannula relative to its longitudinal axis and inhibits or prevents the disruption tip from puncturing through or damaging the cortical bone.
[0123] An example of one embodiment of the device having suitable characteristics to prevent or inhibit drilling through cortical bone is shown below in Table 3.
TABLE-US-00003 TABLE 3 To avoid drilling through cortical bone, with large torque value. Characteristics: Blunt tip Flexibility RPM Tip Diameter Attribute: Radius, width, <50 grams to 220 0.127 in diameter deflect range
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[0125] For instance, as the disruption tip 28 is rotated while being advanced through the bone cavity along a first path of travel the tip 28 may encounter a surface of cortical bone. Because of the configuration of the tip 28 having the specified shape and dimensions, e.g., radius, arc, thickness, etc. described herein, the tip 28 may deflect against the cortical bone surface without damaging the cortical bone while still disrupting the bone marrow matrix.
[0126] In this manner, the tip 28 may be deflected along a different path until it encounters another surface of cortical bone where it may be deflected yet again along another path, and so on during treatment. For instance, one particular variation of the disruption tip 28 having a thickness of 0.032 in. and a radiused portion of between 0.005 in. and 0.010 in. which extends over a central are of between 100° and 120° provides a configuration which enables the tip 28 to redirect the cannula in one or more directions while being rotated about a longitudinal axis upon encountering a cortical bone surface. If the disruption tip 28 were configured without the radius, arc, and thickness described herein, the tip 28 would likely damage or otherwise drill through the cortical bone.
[0127] In addition, the coiled structure of the second portion 24 in combination with the radiused distal edge of the disruption tip 28 can allow the aspiration cannula 18 to advance through larger regions of the donor's bone cavity without requiring the surgeon to continuously create new entry sites 202 into the donor's bone cavity. Moreover, the coiled structure of the second portion 24 in combination with the radiused distal edge of disruption tip 28 can allow the aspiration cannula 18 to disrupt and aspirate more cancellous bone matrix or bone marrow without requiring the surgeon to retrieve and re-access the donor's bone cavity multiple times. Furthermore, the coiled structure of the second portion 24 in combination with the radiused distal edge of disruption tip 28 can allow the disruption tip 28 to be deflected or change directions within the donor's bone cavity without inadvertently puncturing or penetrating the donor's cortical bone wall. In addition, the coiled structure of the second portion 24 in combination with the radiused distal edge of disruption tip 28 can allow the disruption tip 28 to continuously rotate while being deflected.
[0128] It is apparent to one skilled in the art that various changes and modifications can be made to this disclosure, and equivalents employed, without departing from the spirit and scope of the invention. Elements shown with any variation are exemplary for the specific variation and can be used on or in combination with any other variation within this disclosure.